<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>纵向导航菜单+二级弹出菜单</title>
    <style>
        #div_head{
            height: 100px;
            background-color: #c2fafa;
            margin: 10px 200px;
            font-family: 华文楷体;
            font-size: 30px;
            text-align: center;
            line-height: 100px;
        }
        #div_left{
            width: 200px;
            float: left;
            margin-left: 200px;
        }
        #div_right{
            height: 800px;
            margin-left: 400px;
            margin-right: 200px;
            background-color: #dcf3dc;
        }
        /*去除列表样式*/
        ul{
            list-style-type: none;
            margin: 0;
            padding: 0;
        }
        /*超链接文字颜色*/
        ul li a{
            color: black;
            text-decoration: none;
            font-family: 华文楷体;
            font-size: 20px;
        }
        /*列表属性*/
        ul li{
            width: 100px;
            height: 50px;
            background-color: #dde0e0;
            text-align: center;
            line-height: 50px;
            border-bottom: 1px dashed black;
            position: relative;
        }
        a:hover{
            color: red;
        }
        ul li a ul{
            display: none;
        }
        ul li a:hover ul{
            color:black;
            display: block;
            position: absolute;
            left: 100px;
            top: 0px;
        }
        ul li a ul li{
            width: 80px;
            background-color: #f1f5f5;
        }

        /*表格样式*/
        #tab,td,th{
            border: 1px solid #ccc;
        }
        #tab{
            width: 70%;
            line-height: 45px;
            margin: 0 auto;
            border-collapse: collapse;
            text-align: center;
            font-family: 华文楷体;
        }
        tr:hover{
            background-color: #dbf3f3;
        }
        tr:nth-child(odd){background-color: #eaecec}
        /*超链接*/
        table a{
            text-decoration: none;
        }
        table a:link{color: blue}
        table a:visited{color: chartreuse}
        table a:hover{color:red}
        table a:active{color:black}

    </style>
</head>
<body>
    <div id="div_head">
        这是菜单栏
    </div>
    <div id="div_left">
        <ul>
            <li><a href="#">论坛
                <ul>
                    <li>111</li>
                    <li>222</li>
                    <li>333</li>
                </ul>
            </a></li>
            <li><a href="#">说明文档</a></li>
            <li><a href="#">帮助</a></li>
            <li><a href="#">论坛</a></li>
            <li><a href="#">说明文档</a></li>
            <li><a href="#">帮助</a></li>
        </ul>
    </div>
    <div id="div_right">
        <table id="tab">
            <tr>
                <th>姓名</th>
                <th>年龄</th>
                <th>性别</th>
                <th>个人介绍</th>
            </tr>
            <tr>
                <td>张三</td>
                <td>18</td>
                <td>男</td>
                <td><a id="a1" href="css_demo5.html">请点击</a></td>
            </tr>
            <tr>
                <td>张三</td>
                <td>18</td>
                <td>男</td>
                <td><a id="a2" href="css_demo5.html">请点击</a></td>
            </tr>
            <tr>
                <td>张三</td>
                <td>18</td>
                <td>男</td>
                <td><a id="a3" href="css_demo5.html">请点击</a></td>
            </tr>
            <tr>
                <td>张三</td>
                <td>18</td>
                <td>男</td>
                <td><a id="a4" href="css_demo5.html">请点击</a></td>
            </tr>
        </table>
    </div>

</body>
</html>